<template> 
  <div> 
    <div class="goods"> 
      <div class="menu-wrapper"> 
        <ul>
          <li class="menu-item" v-for="(good, index) in goods" :key="index"
              :class="{current: index === currentIndex}"  @click="selectMenuItem(index)"> 
            <span class="text bottom-border-1px">
              <img class="icon" :src="good.icon" v-if="good.icon"> 
              {{good.name}}
            </span>
          </li> 
        </ul> 
      </div> 
      <div class="foods-wrapper">
        <ul ref="foodsUl">
          <li class="food-list-hook" v-for="(good, index) in goods" :key="index"> 
            <h1 class="title">{{good.name}}</h1> 
              <ul>
                <li class="food-item bottom-border-1px" v-for="(food, index) in good.foods" :key="index"
                    @click="showFood(food)"> 
                  <div class="icon"> 
                    <img width="57" height="57" :src="food.icon"> 
                  </div> 
                  <div class="content"> 
                    <h2 class="name">{{food.name}}</h2> 
                    <p class="desc">{{food.description}}</p> 
                    <div class="extra"> 
                      <span class="count">
                        月售 {{food.sellCount}} 份
                      </span> 
                      <span>
                        好评率 {{food.rating}}%
                      </span>
                    </div> 
                    <div class="price"> 
                      <span class="now">￥{{food.price}}</span> 
                    </div> 
                    <cart-control :food="food" />
                  </div> 
                </li> 
              </ul> 
          </li>
        </ul> 
      </div> 
    </div>
    <shop-cart/>
    <transition name="fade">
      <Food :food="selectFood" v-show="foodShow" @hiddenFood="hiddenFood"/>
    </transition>
  </div> 
</template>

<script>
import BScroll from 'better-scroll'
import {mapState} from 'vuex'
import CartControl from '../../../components/CartControl/CartControl.vue'
import Food from '../../../components/Food/Food.vue'
import ShopCart from '../../../components/ShopCart/ShopCart.vue'

export default {
  components: { 
    CartControl,
    Food,
    ShopCart
  },
  mounted () {
    this.$store.dispatch('reqShopGoods', () => {
      this.$nextTick (() => {
        this._initScroll()
        this._initTops()
      }) 
    })
  },
  data () {
    return {
      scrollY: 0, // 右侧滑动的Y轴坐标
      tops: [], // 所有右侧分类li的top值组成的数组
      selectFood: {},
      foodShow: false
    }
  },
  computed: {
    ...mapState(['goods']),
    currentIndex () {
      // 使用scrollY 和tops 属性比较得到结果
      const {scrollY, tops} = this
      // 比较确定index
      let index = tops.findIndex((top, index) => {
        return (scrollY >= top && scrollY < tops[index+1])
      })
      // console.log(index)
      return index
    }
  },
  methods: {
    _initScroll () { // 滚动条初始化
      new BScroll('.menu-wrapper', {
        click: true
      })
      this.foodsScroll = new BScroll('.foods-wrapper', {
        probeType: 1,
        click: true
      })
      this.foodsScroll.on('scroll', ({x, y}) => {
        // console.log(x, y)
        this.scrollY = Math.abs(y)
        // console.log(this.scrollY)
      }),
      this.foodsScroll.on('scrollEnd', ({x, y}) => {
        // console.log(x, y)
        this.scrollY = Math.abs(y)
        // console.log(this.scrollY)
      })
    },
    _initTops () {
      // 初始化 tops
      const tops = []
      let top =0
      tops.push(top)
      // 收集tops
      const lis = this.$refs.foodsUl.children
      // console.log(lis)
      Array.prototype.slice.call(lis).forEach(li => {
        // top += li.clientHeight
        top += li.offsetHeight
        tops.push(top)
      })
      // 返回tops
      this.tops = tops
      // console.log(tops)
    },
    selectMenuItem (index) {
      const scrollY = this.tops[index]
      this.scrollY = scrollY
      this.foodsScroll.scrollTo(0, -scrollY, 200)
    },
    showFood (food) {
      this.selectFood = food
      this.foodShow = true
    },
    hiddenFood () {
        this.foodShow = false
    }
  }
}
</script>

<style lang="stylus" rel="stylesheet/stylus"> 
@import "../../../common/stylus/mixins.styl" 
.fade-enter-active,.fade-leave-active
  transition all .2s
.fade-enter,..fade-leave-to
  opacity 0
.goods 
  display: flex 
  position: absolute 
  top: 195px 
  bottom: 46px 
  width: 100% 
  background: #fff; 
  overflow: hidden 
  .menu-wrapper 
    flex: 0 0 80px 
    width: 80px 
    background: #f3f5f7 
    .menu-item 
      display: table 
      height: 54px 
      width: 56px 
      padding: 0 12px 
      line-height: 14px 
      &.current 
        position: relative 
        z-index: 10 
        margin-top: -1px 
        background: #fff 
        color: $green
        font-weight: 700 
        .text 
          border-none() 
      .icon 
        display: inline-block 
        vertical-align: top 
        width: 12px 
        height: 12px 
        margin-right: 2px 
        background-size: 12px 12px 
        background-repeat: no-repeat 
      .text 
        display: table-cell 
        width: 56px 
        vertical-align: middle 
        bottom-border-1px(rgba(7, 17, 27, 0.1)) 
        font-size: 12px 
  .foods-wrapper 
    flex: 1 
    .title 
      padding-left: 14px 
      height: 26px 
      line-height: 26px 
      border-left: 2px solid #d9dde1 
      font-size: 12px 
      color: rgb(147, 153, 159) 
      background: #f3f5f7 
    .food-item 
      display: flex 
      margin: 18px 
      padding-bottom: 18px 
      bottom-border-1px(rgba(7, 17, 27, 0.1)) 
      &:last-child 
        border-none() 
        margin-bottom: 0 
      .icon 
        flex: 0 0 57px 
        margin-right: 10px 
      .content 
        flex: 1 
        .name 
          margin: 2px 0 8px 0
          height: 14px 
          line-height: 14px 
          font-size: 14px 
          color: rgb(7, 17, 27) 
        .desc, .extra 
          line-height: 10px 
          font-size: 10px 
          color: rgb(147, 153, 159) 
        .desc 
          line-height: 12px 
          margin-bottom: 8px 
        .extra 
          .count
            margin-right: 12px 
        .price 
          font-weight: 700 
          line-height: 24px 
          .now
            margin-right: 8px 
            font-size: 14px 
            color: rgb(240, 20, 20) 
          .old
            text-decoration: line-through 
            font-size: 10px 
            color: rgb(147, 153, 159) 
        .cartcontrol-wrapper 
          position: absolute 
          right: 0 
          bottom: 12px 
</style>
